Determining cleanliness of various items is important in many different industries. For example, developers of cleaning agents judge the effectiveness of a newly developed cleaning agent based on how clean a ware becomes after applying the cleaning agent. Restaurateurs determine cleanliness of dishes, glasses, cooking utensils, and eating utensils for sanitary and aesthetic purposes, e.g., to determine whether a particular ware is suitable for use or whether the ware must be re-washed after a first washing. Launderers may similarly determine whether laundry is clean for aesthetic purposes, e.g., to determine whether to re-wash a particular laundry item.
In many industries, a trained expert judges the cleanliness of an item via a visual inspection process and provides feedback as to the cleanliness of the item. In an attempt to quantify the meaning of the term “cleanliness,” standardized cleanliness scales for different industries have been developed. In that case, an expert may provide a cleanliness rating as a numeric value on a standardized cleanliness scale. However, the use of experts requires reliance on subjectivity, as well as the time and expense to train a person to become an expert at determining cleanliness of a particular item.